What annoys me today in marketing and media that too often today then talking on hi-fi, science is replaced by bizarre belief structures and marketing fluff, leading to a decades-long stagnation of the audiophile domain. Science makes progress, pseudo-science doesn’t. Hi-fi world is filled by pseudoscience, dogma and fruitloopery to the extent that it resembles a fundamentalist religion. Loudspeaker performance hasn’t tangibly improved in forty years and vast sums are spent addressing the wrong problems.
Business for Engineers: Marketers Lie article points tout that marketing tells lies — falsehoods — things that serve to convey a false impression. Marketing’s purpose is to determining how the product will be branded, positioned, and sold. It seems that there too many snake oil rubbish products marketed in the name of hifi. It is irritating to watch the stupid people in the world be fooled.
In EEVblog #29 – Audiophile Audiophoolery video David L. Jones (from EEVBlog) cuts loose on the Golden Ear Audiophiles and all their Audiophoolery snake oil rubbish. The information presented in Dave’s unique non-scripted overly enthusiastic style! He’s an enthusiastic chap, but couldn’t agree more with many of the opinions he expressed: Directional cables, thousand dollar IEC power cables, and all that rubbish. Monster Cable gets mostered. Note what he says right at the end: “If you pay ridiculous money for these cable you will hear a difference, but don’t expect your friends to”. If you want to believe, you will.
My points on hifi-nonsense:
One of the tenets of audiophile systems is that they are assembled from components, allegedly so that the user can “choose” the best combination. This is pretty largely a myth. The main advantage of component systems is that the dealer can sell ridiculously expensive cables, hand-knitted by Peruvian virgins and soaked in snake oil, to connect it all up. Say goodbye to the noughties: Yesterday’s hi-fi biz is BUSTED, bro article asks are the days of floorstanders and separates numbered? If traditional two-channel audio does have a future, then it could be as the preserve of high resolution audio. Sony has taken the industry lead in High-Res Audio.
HIFI Cable Humbug and Snake oil etc. blog posting rightly points out that there is too much emphasis placed on spending huge sums of money on HIFI cables. Most of what is written about this subject is complete tripe. HIFI magazines promote myths about the benefits of all sorts of equipment. I am as amazed as the writer that that so called audiophiles and HIFI journalists can be fooled into thinking that very expensive speaker cables etc. improve performance. I generally agree – most of this expensive interconnect cable stuff is just plain overpriced.
I can agree that in analogue interconnect cables there are few cases where better cables can really result in cleaner sound, but usually getting any noticeable difference needs that the one you compare with was very bad yo start with (clearly too thin speaker wires with resistance, interconnect that picks interference etc..) or the equipment in the systems are so that they are overly-sensitive to cable characteristics (generally bad equipment designs can make for example cable capacitance affect 100 times or more than it should). Definitely too much snake oil. Good solid engineering is all that is required (like keep LCR low, Teflon or other good insulation, shielding if required, proper gauge for application and the distance traveled). Geometry is a factor but not in the same sense these yahoos preach and deceive.
In digital interconnect cables story is different than on those analogue interconnect cables. Generally in digital interconnect cables the communication either works, does not work or sometimes work unreliably. The digital cable either gets the bits to the other end or not, it does not magically alter the sound that goes through the cable. You need to have active electronics like digital signal processor to change the tone of the audio signal traveling on the digital cable, cable will just not do that.
But this digital interconnect cables characteristics has not stopped hifi marketers to make very expensive cable products that are marketed with unbelievable claims. Ethernet has come to audio world, so there are hifi Ethernet cables. How about 500 dollar Ethernet cable? That’s ridiculous. And it’s only 1.5 meters. Then how about $10,000 audiophile ethernet cable? Bias your dielectrics with the Dielectric-Bias ethernet cable from AudioQuest: “When insulation is unbiased, it slows down parts of the signal differently, a big problem for very time-sensitive multi-octave audio.” I see this as complete marketing crap speak. It seems that they’re made for gullible idiots. No professional would EVER waste money on those cables. Audioquest even produces iPhone sync cables in similar price ranges.
HIFI Cable insulators/supports (expensive blocks that keep cables few centimeters off the floor) are a product category I don’t get. They typically claim to offer incredible performance as well as appealing appearance. Conventional cable isolation theory holds that optimal cable performance can be achieved by elevating cables from the floor in an attempt to control vibrations and manage static fields. Typical cable elevators are made from electrically insulating materials such as wood, glass, plastic or ceramics. Most of these products claim superior performance based upon the materials or methods of elevation. I don’t get those claims.
Along with green magic markers on CDs and audio bricks is another item called the wire conditioner. The claim is that unused wires do not sound the same as wires that have been used for a period of time. I don’t get this product category. And I don’t believe claims in the line like “Natural Quartz crystals along with proprietary materials cause a molecular restructuring of the media, which reduces stress, and significantly improves its mechanical, acoustic, electric, and optical characteristics.” All sounds like just pure marketing with no real benefits.
CD no evil, hear no evil. But the key thing about the CD was that it represented an obvious leap from earlier recording media that simply weren’t good enough for delivery of post-produced material to the consumer to one that was. Once you have made that leap, there is no requirement to go further. The 16 bits of CD were effectively extended to 18 bits by the development of noise shaping, which allows over 100dB signal to noise ratio. That falls a bit short of the 140dB maximum range of human hearing, but that has never been a real goal. If you improve the digital media, the sound quality limiting problem became the transducers; the headphones and the speakers.
We need to talk about SPEAKERS: Soz, ‘audiophiles’, only IT will break the sound barrier article says that today’s loudspeakers are nowhere near as good as they could be, due in no small measure to the presence of “traditional” audiophile products. that today’s loudspeakers are nowhere near as good as they could be, due in no small measure to the presence of “traditional” audiophile products. I can agree with this. Loudspeaker performance hasn’t tangibly improved in forty years and vast sums are spent addressing the wrong problems.
We need to talk about SPEAKERS: Soz, ‘audiophiles’, only IT will break the sound barrier article makes good points on design, DSPs and the debunking of traditional hi-fi. Science makes progress, pseudo-science doesn’t. Legacy loudspeakers are omni-directional at low frequencies, but as frequency rises, the radiation becomes more directional until at the highest frequencies the sound only emerges directly forwards. Thus to enjoy the full frequency range, the listener has to sit in the so-called sweet spot. As a result legacy loudspeakers with sweet spots need extensive room treatment to soak up the deficient off-axis sound. New tools that can change speaker system designs in the future are omni-directional speakers and DSP-based room correction. It’s a scenario ripe for “disruption”.
Computers have become an integrated part of many audio setups. Back in the day integrated audio solutions in PCs had trouble earning respect. Ode To Sound Blaster: Are Discrete Audio Cards Still Worth the Investment? posting tells that it’s been 25 years since the first Sound Blaster card was introduced (a pretty remarkable feat considering the diminished reliance on discrete audio in PCs) and many enthusiasts still consider a sound card an essential piece to the PC building puzzle. It seems that in general onboard sound is finally “Good Enough”, and has been “Good Enough” for a long time now. For most users it is hard to justify the high price of special sound card on PC anymore. There are still some PCs with bad sound hardware on motherboard and buttload of cheap USB adapters with very poor performance. However, what if you want the best sound possible, the lowest noise possible, and don’t really game or use the various audio enhancements? You just want a plain-vanilla sound card, but with the highest quality audio (products typically made for music makers). You can find some really good USB solutions that will blow on-board audio out of the water for about $100 or so.
Although solid-state technology overwhelmingly dominates today’s world of electronics, vacuum tubes are holding out in two small but vibrant areas. Some people like the sound of tubes. The Cool Sound of Tubes article says that a commercially viable number of people find that they prefer the sound produced by tubed equipment in three areas: musical-instrument (MI) amplifiers (mainly guitar amps), some processing devices used in recording studios, and a small but growing percentage of high-fidelity equipment at the high end of the audiophile market. Keep those filaments lit, Design your own Vacuum Tube Audio Equipment article claims that vacuum tubes do sound better than transistors (before you hate in the comments check out this scholarly article on the topic). The difficulty is cost; tube gear is very expensive because it uses lots of copper, iron, often point-to-point wired by hand, and requires a heavy metal chassis to support all of these parts. With this high cost and relative simplicity of circuitry (compared to modern electronics) comes good justification for building your own gear. Maybe this is one of the last frontiers of do-it-yourself that is actually worth doing.
1,887 Comments
Tomi Engdahl says:
capacitor types can make difference also when the capacitor type is not “right” for the application.
Electrolytic and some ceramic capacitors have bad sound reputation on certain applications for a reason. In some applications you can benefit noticeably by changing the “wrong” capacitor type to “right” type. Getting right type and decent quality capacitor will do, I have not noticed any noticeable benefits above that when some people have gone to expensive special audio capacitors.
Tomi Engdahl says:
Capacitors
https://www.facebook.com/groups/DIYAudio/permalink/4503337329732078/
On the absolute Nichicon KZ signal. When used in Nichicon FG / FW digital. The MKP10s are the absolute best as a bypass or on the signal. For large capacitors the Epcos are very good (Ex Siemens Sikorel), but I prefer the Kemet. In the small power supply the Nichicon KG on the digital while on the analogue Nichicon KX (exceptional). Panasonic’s have great ESR but sound too warm and mellow (I don’t like them). This in summary.
Tomi Engdahl says:
Capacitors
https://m.facebook.com/groups/DIYAudio/permalink/4501715176560960/
These are all the “audio” capacitors you’ll ever need; Wima MKP (up to and including 1uF) and Nichicon Muse ES bipolar electrolytics (larger than 1uF) for any signal coupling and filtering duties.
Tomi Engdahl says:
Read the late Cyril Bateman’s articles on capacitor distortions.
https://linearaudio.nl/cyril-batemans-capacitor-sound-articles
Tomi Engdahl says:
With a subject like „audio“, we now have word police next to the angry electricians. We now have proof that some only believe numbers generated by a multimeter. Human perception seems to be a science conveniently ignored – that is funny as it IS well researched and accepted.
The words „physics“ or AB testing are thrown around, but the context shows little understanding of how that could fit in an audio context.
This hobby should be about enjoyment at any level of perception that one happens to be. Not recognizing and embracing that, means that we have no sensations to share, we have no frame of discussion except at kindergarden level name calling „snake oil“, deaf, blind or any othe explicative that one cares to choose.
Stereo playback has many more serious issues than caps right from the git go. Home theater generally completes the desaster. Comb filtering, phase distortion, bad recordings for reference purposes, bad positioning of speakers, faulty speaker designs and perhaps the cheapest to fix but most deficient: the listeners understanding of music and artistic intent.
Why discuss the difference in part quality if we have no personal need? Cheap parts can still get flat frequency response and low distortion.
If we start to talk about „tone“ or „articulation“ it is useful to know what that is and how it applies to the enjoyment of music.
Tomi Engdahl says:
How to identify the weak link in an audio system
https://www.youtube.com/watch?v=lVTNG5hWk6M
Finding the weakest link for replacement can be difficult. Paul walks us through.
Video comments:
“I like the sound – ” Stop right there. Why change? You’ve found the sweet spot. So many audiophiles will never be happy with what they have because they get addicted to ‘upgrading’ (in reality, often merely expensively changing) their system in search of the myth of a perfection that doesn’t exist. Your system makes you happy, so you’re free to spend your money instead on expanding your music collection!
Chasing the dragon.
I disagree, if you’re closed to new opportunities you don’t know if theres anything you’re missing
More music is the best upgrade for any system.
Here’s the thing, though. No system is perfect in every way. Every single audiophile is missing something. The hard thing, if you’re a perfectionist (as many audiophiles are), is to let it go.
There’s always room for improvement, but he isn’t being too specific on what he feels his system lacks. Identifying that would be really helpful. Paul’s probably right about the speakers in any case.
Speaker placement. Room acoustics and speakers . Don’t know what speakers you are running. Look inside , are they braced, do they have material lining the cabinets, are the crossovers proper (not just a cap and resister on the tweeter)made from decent components? How low do the speakers play? Do you need a sub?
Speakers can sound different and people have their opinions on what sound good to them.
Tomi Engdahl says:
LM4562 > NE5532 > TL072
Reading the datasheets.
See:
- Distortion
- Noise
- Open loop gain
- PSRR & CMRR
- Slew
Tomi Engdahl says:
NE5532 original for high gain low noise
Tomi Engdahl says:
Balanced is better especially for long cables where you could get more noise
About other points, it is important to check impedance of output and input to be sure it matches in the right way
A balanced 1/4” output is identical in sound quality to an XLR output. They both have the same three conductors.
TRS and XLR are the same thing, different geometry. RCA and TS are the same thing except geometry. If you monitor inputs are separate XLR and TRS, then you’re better off with TRS, because XLR goes thru the TRS, and is switched inside the TRS switched jack. So TRS adds more wire, and contact resistance. If you monitor has combo XLR/TRS, then you’re probably better off with XLR(better shielding).
If one side is only unbalanced, then use TS-TS cable(with one exception, as specified in the following), otherwise 1 wire will be floating, causing 6dB signal loss, or complete disconnect, depending on the signal. If Output(from mixer) is unbalanced, but the monitor input is balanced, you can use any TS-TS, or TRS-TRS cable. If the Output is balanced but the input is unbalanced, then do not use TRS-TRS.
The only people I know who use rca are edm dj’s. And it always blows my mind when they wonder why their shit almost always sounds crappy. Thousands in equipment 4$ in cables
I think youre confusing balanced with stereo. No such thing as balanced content
I guess the last, main question I have is if there is any auditory difference between 1/4 TRS or XLR?
No. Any difference probably is not even measurable. They just have a 2 inch wire between them.
RCA (unbalanced signal) works okay for short distances as long as it has a large signal to noise ratio (output is loud enough to drown the noise, but quiet enough to not distort the inputting device) if that makes sense. Balanced signals (such as an XLR) are far superior for noise rejection and get you a much better signal to noise ratio, especially when working with cables greater than 10′ in length. Balanced signals work by having a + and – signal wire. having them be on separate wires means that the noise picked up by the cabling can easily be nullified at the destination as it can fact check between the two lines of signal. with only one line of signal, the receiving device must accept whatever audio it gets including noise, and thus it amplifies it. hope this helps.
in the case of the CDJ’s, the audio goes three feet to a mixer, which in most professional settings is converted into XLR shortly thereafter or within the mixer board itself. In consumer audio the same exists, as it goes from hte CD player or FM tuner to the amp directly beneath it. On A stage or in a venue, cabling travels much farther. Unbalanced sources will pick up all sorts of noise, such as AM radio, Electric motors (think HVAC blowers/compressors, refrigeration, etc.
Tomi Engdahl says:
https://www.facebook.com/groups/DIYAudio/permalink/4512699005462577/
Lets talk about degradation due to use of
basic Carbon pot
is Alps Pot much better?
relayvolume with fix resistors fancy item
how good are they?
I have used both. There really isn’t a “better” unless you are talking about channel matching in which case the relays or stepped attenuators are better. I like the cheap smd dact attenuators off eBay…they are good. But carbon pots have a “sound” which you might like. Tocos cosmos are good, blue velvet is supposed to be nice. If your preamp is too dry and clinical I’d try a carbon pot. Too warm go with a relay or ladder.
Yes the alps is much better than a bog standard carbon pot. Tracking is more than reasonable yes stepped will be better, will you really notice… Umm. Stepped attenuator can be better however finding a decent stereo step attenuator with enough steps to give a good volume range without big steps will be more costly. Relays will also be more difficult and involved to implement. Pay your money take your choice. It also depends what this is being fitted into be realistic.
How good does the rest of the system have to be to „hear“ differences in volume controls. After that, how much better does it have to be to define the „differences“ as „better“. The matrix with relays and resistors is convenient IF you want a remote control. I would want volume 128 steps.
As always, Rod Elliot has published an excellent article on this. Rod argues that logarithmic pots are less reliable than linear pots – and more expensive. You can use a linear pot with a load resistor to make it logarithmic. I do this and it works well. It means you have a much wider choice of good inexpensive linear pots too! https://sound-au.com/project01.htm
Real ALPS pots are a good device, certainly better than your basic “no-name” carbon pot. Price is reasonable too.
Basic cheap pots work better if you run separate left and right volume controls rather than a “stereo” pot. Then they “track” as good as you hear…….
Had Bourns volume control pots. Small signal loss at low volume setting and channel imbalance. Alps blue velvet is the best poor-mans volume control pot. It is a stepped attenuator. I forget what size SMD resistors are used but they are small.
Alps are crap, I pulled one out my Exposure Pre and put in a Panasonic. Much more open sound. Noble are good as well if you can find one.
ALPS *carbon composition* pots are no better than anyone else’s carbon composition pots.
But their 25mm and 40mm conductive plastic potentiometers are much quieter than any carbon comp and they will stay that way for a lifetime.
alps rk27 the blue ones is 20% specs so not very precise or usefull for stereo , carbon types also have 20% tolerance between channels https://tech.alpsalpine.com/prod/e/html/potentiometer/rotarypotentiometers/rk271/rk27112a0a16.html
You could always use a rottary multi contact switched fixed value resistor chain?
Tomi Engdahl says:
From https://www.facebook.com/groups/DIYAudio/permalink/4510187059047105/
I’m re-capping all the electrolytic capacitors in a Yamaha C-6 preamplifier.
The main power/filter caps are 470uf 50v
I got new nichicon muse caps in there now. But I also ordered the same value elna slimic II.
Elna caps are always more expensive, not sure if that means anything.
Should I keep the muze in there, or put in the elnas?
P.S. – I’ve used elna slimic where possible, and nichicon FG elsewhere. The BP caps are nichicon green caps. I’m almost done.
Any decent electrolytic capacitor is fine in the power supply, don’t fall for the “audio” part marketing. The only difference any of those make is imagined by the listener
I just go with polymer electrolytics such as Wurth.
If you want to do something meaningful bypass either lytic with a 4.7uf film cap and a .1uf film cap.
may not provide any improvement…
i know that should be done for some applications but my understanding is it should be done on a case by case basis
Lower the impedance across the audio range remains low, the large lytics have a greatly degraded ear at higher frequencies , remember the power supply is always in series with your amp and is the current return
In a preamp, anything 4.7uf and smaller that are currently electrolytic’s could be changed out with films (Wima) or Nichicon UKL. UES are fine for bipolars. I would use Mundorf for power filters – The MLytic AG · Power Cap @ 1000 uf – just confirm your in-rush current. Unless you want to go cheap, then UPW will work @ 570 or 680 uf.
what is the benefit of swapping a electrolytic with a film? I’m new to this.
they are far more stable, longer life, lower esr and much cleaner sounding. You would use them for the higher uf but they get be the size of beer cans at these values. Any artificial distortions or discoloration created in a preamp gets significantly amplified down the chain. The wimas come in 2.5 and 5 mm pin widths so on many cases can drop right in.
Film caps have less leakage(most important feature for line level audio), and they dont dry up(which means they can last indefinitely).
Saying that capacitors don’t impact amplifier’s sound is total ignorance!
Filter capacitors do have an impact on the sound, because they are the ones who actually supply the power to the amplifier most of the time. Remember that they are charged 100 (or 120) times a second by very brief impulses from the transformer and rectifier, while amplifier draws the current all the time, depending on the signal.
Capacitors main characteristic is their capacitance, however, they also have some inductance and resistance. Plus there’s voltage, temperature, then there are mechanical properties, microphonic effect, etc., all of which have a rather complex interaction – and a huge impact on the waveform of the current and voltage that they provide.
A good amplifier designer takes this entire set of capacitors’ characteristics into account during the design process, so it would be best, if possible, to replace them with the same (or similar) like originals. Otherwise, your amplifier will never sound the same again.
different types do impact the amps sound but the claim that “audio grade” is superior to all others has never been proven
Audio grade means very low ESR and inductance, but more importantly, it means excellent mechanical properties. Capacitor’s capacitance is directly dependent on the surface of the plates, distance between them and dielectric that prevents electron exchange between them. When the plates are charged, they attract each other – so it affects distance between them, and ultimately, their capacitance. When they warm up they expand, so their size and distance changes – again influencing capacitance. When they vibrate – the same happens again. All this inevitably affects audio signal passing through. When capacitor designers say “audio grade”, it means they addressed these issues.
Tomi Engdahl says:
https://www.facebook.com/groups/DIYAudio/permalink/4512621362137008/
if you insist on replacing the input caps use the Nichicon Fine Gold UFG don’t waste your time with the KZ. I have a/b the FG are the best.
I have yet to replace SMD caps but have had huge sonic differences by doing mods like this trial and error let us know what you find out http://www.humblehomemadehifi.com/Cap.html
Arild did they ever define their test methodology? From all the adjectives topped about seems like there is a lot of imagination in play
This can be a crapshoot for sure Humble hifi has done something no one else has done and personally, I appreciate his efforts and find them valuable. I am sure the individual objective listening experiences would differ but in my experience, he is not far off. try it for yourself spend the money give some constructive feedback on your findings I would love to hear them. I have experienced positive and negative improvements by doing this, but you will not know until you try?
SMSL SP200 Components Analysis
https://orronoco.blogspot.com/2020/03/smsl-sp200-components-analysis.html?m=1
this is not the best components analysis, even that there was a guy in the comments who did a better job.
nah man, hi performance caps already on here. at most leave solid SMD alone and replace standard electros, but check their spec first, but i think theyre good to begin with
If it ain’t broke don’t fix it
Try to keep electrolytic caps out of Analog signal paths: I would use WIMA’s or other quality metal film capacitors .
Don’t do anything. If you want better, buy better. The engineer knew what he was doing, and I see this is the general theme here. Leave it alone. Just enjoy music
Tomi Engdahl says:
https://www.facebook.com/groups/517919938413134/permalink/1644152472456536
So what do people like for matching transformers for input and output (mic preamp project). I know price dictates quality, but hopefully affordable too. I bought and liked some of the Edcor and Hammond stuff, but curious what else is out there. TIA
OEP are not bad for low price…
then Lundahl for EU and cinemag in US…
Depends what design topology, configuration and ratio you need. Carnhill, Sowter, AMI, numerous manufacturers.
Jensen transformers in the USA are also very well regarded
Tomi Engdahl says:
https://m.facebook.com/groups/DIYAudio/permalink/4518312491567895/
Doesn’t having a Class A Amplifier bang up your electricity Bill? Is Class A really the best type of Amplier to build? Isn’t it expensive to build and run? Why not Class A/B ? Your thoughts are welcome. If anybody can pursuade me, I may just build one. Might take me a couple of years though, like my Valve phono clone. Lol
> Doesn’t having a Class A Amplifier bang up your electricity Bill?
It depends how much time it is turned on and how much power it consumes.
If it is powerful amplifier, you keep it on all the time and your air conditioning needs to take out heat, it will quicly cost a considerable amount of money.
If you listen to it few hours a week not that much. If you live in cold country on house with electrical heating needed most of year, most heat from amplifier is reused for house heating instead of using power for that.
> Is Class A really the best type of Amplier to build?
Many audiophiles say it is the “gold standard” of amplifier types.
It has it’s own plus and minus sides like all amplifier types.
It is debatable if it is the best or not.
> Isn’t it expensive to build and run?
Depends entrily on the amplifier design and power rating of it. Generally for same output power class A amplifier is more expensive to make than class AB or class D because for class A bigger power transformers and much bigger heatsinks are needed (etc.) for transistor amplifier.
> Why not Class A/B ?
Why not class AB or class D instead is good question that does not have one single right answer. It depends on many things and your preferences.
My overall impression is that class A distortion generally is better sounding opposed to a class AB distortion. What i’m seeing so far is that big bias currents tend to create more dominant 2nd harmonic. Even harmonics never sound dissonant and therefore a steaming hot bias might sound better. Of course there’ll be less crossover distortion but in a good class AB amp this can be brought down to non audible.
From a DIY perspective Class A is often much easier to build. Circuit is far simpler than a Class D as well as a lot of Class AB amps.
Class A is less efficient but from my perspective it doesn’t matter so much if you use electric heating.
Class A will cost a lot if you need +100W. But for a low powered system it’s not that bad.
For anything that has low current output (preamp, DACs, phono, etc) I prefer Class A circuits. If I need power I use Class AB and Class D for subs.
The only advantage of running an amp is Class A is the elimination of crossover distortion caused when the devices are turning on and off. Good quality Class AB amps do a fine job of all but eliminating the problem also. If Class A we’re as awesome as some say it would be standard on the vast majority of quality amplifiers, but somehow it remains an outlier…. Subjective reviews by biased listeners are the biggest reason it remains a thing.
Tomi Engdahl says:
Technically there are 3-4 reasons why Class A is superior than AB and D. You can see it in the plots and oscilloscopes. But can you hear the difference, and can you reliably pass ABX and pick out which one is which… different matter.
Tomi Engdahl says:
Many people are confused. Class A amplifiers are certainly better than Class B amplifiers. Class A/B amplifiers provide more efficiency than Class A and eliminates the notch distortion of Class B. Class A B is not a compromise. It is an improvement over both class A and Class B. While some will argue that class A is better, it is hard to imagine exactly how.
Tomi Engdahl says:
The big advantage of Class A is that designers can make simpler circuits that are very linear with low distortion at low power, whereas with Class AB designers have to make more complex circuits using feedback to get very low distortion levels but can make significantly more powerful amps
Tomi Engdahl says:
The sonic difference between Class A and AB is mostly because the Class A amps usually have better power supplies and regulation, and are also better built (they have to, as they run very hot).
Tomi Engdahl says:
Nearly every guitar amplifier with multiple output valves will operate in Class AB. Class AB is more efficient that Class A, but less so than Class B.
Tomi Engdahl says:
Class A amplifiers can be made very linear, but with limited efficiency. In theory, a class A amp can achieve 50% efficiency with inductive output coupling or 25% with capacitive coupling. Class B amplifiers are subject to “crossover” distortion, but efficiency runs theoretically as high as 78.5%.
https://www.electronicdesign.com/technologies/analog/article/21801654/understanding-amplifier-operating-classes
Tomi Engdahl says:
Yes, but it’s not as radical as some believe.
I looked up the specs on my 10 watt solid state class A, and it’s a 200 watt constant draw.
I don’t think tube class A amps is that inefficient but I could be wrong.
Joe Woods tube class A amplifier that uses output transformer to drive speaker can be somewhat more efficient than simple transistor based class A direct speaker driving amplifier design.
In theory, a class A amp can achieve 50% efficiency with inductive output coupling or 25% with capacitive coupling.
Source: https://www.electronicdesign.com/technologies/analog/article/21801654/understanding-amplifier-operating-classes
In real life hifi amplifiers optimated for sound quality and in typical operating conditions the efficiency is often considerably lower.
Tomi Engdahl says:
Many people are confused. Class A amplifiers are certainly better than Class B amplifiers. Class A/B amplifiers provide more efficiency than Class A and eliminates the notch distortion of Class B. Class A B is not a compromise. It is an improvement over both class A and Class B. While some will argue that class A is better, it is hard to imagine exactly how.
https://www.sound-au.com/class-a.htm. Rod Elliot wrote an excellent article on this subject. I suggest all his articles.
Tomi Engdahl says:
The output transformer can can introduce distortion. Typically transformer affects frequency response, has frequency dependent phase response isdues, has signal level dependent distortion etc..
Tomi Engdahl says:
Good Question! The correct answer is: It Depends.
1: If you are building a critically clean mic pre, then you don’t necessarily need transformers.
2: If you are building a Tube Pre, then you need transformers.
3: Here, things get weird. What kind of “sound” do you want out of the pre? No distortion, a little distortion, some distortion? Do you want a big, fat low-end? Do you want a “jangly upper mid”?
Define the sound you want first. If perfect transparency is the goal, call Jensen Transformers. If you are looking for something that you can saturate and distort (these can be desirable features), then Sowter is worth a look.
Best of Luck!
Tomi Engdahl says:
The thing with digital is, it either works or doesn’t. Even if it’s not the proper cable, the fact you hear something, means it’s only going to be perfect. Or silence. That does not mean that your connection will stay stable.
almost true, there is still some glitchy area between working and not working – visually evident on digital video cables like HDMI and SDI. You can get cables were most things work, but certain scenes mess up because of the specifics of the electrical signal makeup.
Likewise, if you have a poor quality Cat5e cable for a digital stage box, you can get momentary clicks, pops, drops. They might be quite rare, but they are there.
Tomi Engdahl says:
XLR, RCA, and the Magic of Matching Impedance
https://audiophilereview.com/cables/xlr-rca-and-the-magic-of-matching-impedance/
IMHO, the bulk of the so-called “High-End” cables out there seem to have been designed by someone just like that guy up in the peanut gallery: With no true understanding of how things actually work, their “designers” just seem to have thrown together everything they’ve ever read in somebody else’s “White Paper”; seen in a high school physics text; or picked-up on the internet or in audiophile conversation, and combined it on the assumption that it’s all good, and it can’t possibly hurt – just like that suggested enema. Whether it actually works, though, or is just speculation or wish-fulfilling fantasy seems to be beyond either their ability or desire to determine.
One of the things that sounds technical and that finds a willing audience among both the manufacturers and buyers of cables is the need to very precisely impedance match the connectors and the cables that they are fitted to. All kinds of commentary has been written on that subject, much of it pointing to the “need” to use impedance matching RCA connectors for digital or video applications.
apparently out-of-the-air – people had later come to decide that it was actually a 50 Ohm connector, and that, because of that, it was unsuitable for 75 Ohm digital or video application. I also wrote, in that same article, about how a company called Canare was building RCA connectors that claim – at least when used with Canare’s own 75 Ohm cable – to be a true 75 Ohms. That’s all true, but how important is it? Does it really matter? Or is it just marketing or more amateur orthodoxy? You know what I’m talking about – like the amateur cook very precisely measuring the ingredients for a recipe he’s never made before, it’s the kind of obsessive attention to detail that people who have no solid background in what they’re doing use to give themselves comfort and to hide from others the fact that they don’t really know what they’re doing.
With RCA connectors, the fact that they have only two conductors makes it most likely that they will be used in (shielded or unshielded) unbalanced-line circuits, which probably, except for certain specialized applications like digital and video, will be “loaded” (usually with many times the output impedance of the source component) instead of impedance-matched. In fact, in most unbalanced circuits, impedance matching is simply not possible – the output impedance of the source and the input impedance of the load are wildly different, and there’s simply nothing there to match.
Even so, the range of applications for XLR-type connectors (including the Cannon “X”, and later the “XL” and the “XLR”) has been very broad: Their original application was for 600 Ohm signal transmission. Then, when they were applied to microphones as the standard low-impedance connector, the mics they were built into had impedances ranging all the way from 50 Ohms to 250 Ohms. It was the same thing for balanced line interconnects at all of the same impedances as the microphones.
And, when the AES (Audio Engineering Society) and the EBU (European Broadcasting Union) got together to establish the “AES3” standard (in 1985, as revised in1992 and 2003), for transmitting two (stereo) channels of PCM audio between professional devices, the XLR was the connector they chose for 110 Ohm balanced line application (IEC 60958 Type I).
the XLR connector either really has an impedance of 110 Ohms or that its actual impedance doesn’t matter. There really aren’t any other options. And, given that it has also been used and accepted by the professional audio institutional establishment at other impedances (600, 50, 150, and 250 Ohms) I can only take it as a tacit statement by that institutional establishment that impedance matching of cables and connectors, at least in applications that are of concern to audiophiles, is not a major concern.
There are all kinds of other weird, wonderful, and even outright silly things about cables and their connectors.
Tomi Engdahl says:
Audio interconnect cables explained
http://www.tonestack.net/articles/speaker-building/audio-interconnect-cables.html
Connectors can be RCA, XLR or headphone plugs (also known as TRS or tip-ring-sleeve). Interconnects transmit max. 2 Volt amplitude voltages and the load is more simple than a loudspeaker.
The longest and heaviest ‘interconnects’ on Earth lie deep in the oceans: the transatlantic telecommunication cables and trans-pacific cables. The telephone cables between Europe and North America were in operation until the mid-1990s (today data travels in optical cables) and an average cable had a full bandwidth of 400 kHz (!). The goal was speech intelligibility with as many simultaneous connections as possible and not audio fidelity. The fuss around a few meters long audio cable is really pointless.
For a detailed analysis of interconnect cables we need a relevant electrical model of the full system (equivalent circuit, RC model). If we are interested in our cable’s response up to 100 kHz (which is five times the frequency range of the human hearing!), this simple RC model is perfectly valid up to 200 meters (model is valid for ’75 Ohm’ coaxial cables up to 400 meters). I think that’s enough, this length is far beyond any room size. As we can see the propagation of the electromagnetic wave is negligible in interconnect cables with normal room length.
In the model, the voltage source Ug and the Rg series resistance represent the line out or headphone output. Rin is the input resistance of the amplifier, Uin is the voltage on the input resistor (which will be amplified by the amplifier). Rs is the total resistance of the conductor and the shield, Cp is the capacitance between the conductor and shield. Due to the high input resistance (minimum 600 Ohm), the effect of inductance is negligible, the resistance of the cable does not affect the amplitude response up to a few hundred meters and the skin effect is not significant in audio cables. So we can ignore these in further analysis.
A typical line out has an output impedance from 100 to 600 Ohms, with lower values being more common in newer equipment. Output resistance of headphone connections ranges from 30 to 200 Ohms (although values higher than 100 Ohm are quite rare nowadays). The input resistance falls within 10 kOhm and 100 kOhm. The distributed capacitance of interconnect cables varies between 120-300 pF/m (picofarad per meter).
Line level circuits use the impedance bridging principle, in which a low impedance output drives a high impedance input. In this scenario the dominant parameters are the capacitance of the cable and the output resistance of the source. The output resistance of the signal source (line driver) and the capacitance of the cable forms a low-pass filter. The higher the capacitance of the cable (the longer the cable) and the higher the output resistance of the source, the lower the cut-off frequency. Thus, the frequency response of the cable (and any electronic device) “on its own” is meaningless. Attributing characters like dynamics or soundstage to an interconnect cable is just fantasy.
The graph above shows the low-pass response of a ten meter (32.8 ft) long interconnect cable (TINA simulation). The cable is driven by a voltage source that has a 600 Ohm output resistance. The input resistance is 10 kOhms, the cable’s distributed capacitance is 300 pF/m (so 3000 pF is the total). This is essentially a “worst-case” simulation, as both the 300 pF/meter and the 600 Ohm output resistance can be taken as an upper limit. The difference from the linear response at 20 kHz is 0.21 dB only!
The insulation between the shield and the conductor has a great influence on the distributed capacitance. The two most common materials for wire insulation are polyvinyl chloride (PVC) and polyethylene (PE). The outer jacket is PVC in almost every cable. Typically, cheapest cables have very thin (dia. 1 mm) PVC insulation around the conductor. These cables have a distributed capacitance of 300 pF/m. With polyethylene wire insulation the most common values are 150 pF/m.
There is a small noise filter capacitor (100 pF – 330 pF) at the input of every amplifier, and its role is to prevent radio frequency noise getting into the amp. This capacitance is added to the capacitance of the cable, but it pale into insignificance in the audio range. If we want to be accurate, we can subtract one meter from a 300 pF/m cable (and two meters from a 150 pF/m cable after doubling the values).
With a 600 Ohm line out the full audio frequency band can be transmitted within 0.1 dB error up to 14 meters (46 feet) with a ‘better’ cable and up to 7 meters (23 feet) with a cheapest, high capacitance cable. If we take into account, that modern equipments have much lower output resistance (100 – 200 Ohms), transmitting audio frequency signals in a home audio system shouldn’t be a problem.
Nonlinear distortion is simply non-existent in audio cables. There is no need to deal with nonlinear effects, because if we don’t exceed the 0.5 dB limit at 20 kHz (which requires a long cable), the capacitance and resistance of the insulation (dielectric) will have so tiny effect on the overall response, that even the possibility of the distortion doesn’t exist. The leakage current (dielectric loss) is only significant above 1 MHz even with the worst dielectric (PVC).
We don’t have to be afraid of phase shift (or time smearing) either. Phase shift doesn’t mean anything in itself, what is important is the change in the group delay: the varying time delay in frequency. Even for a ‘large’ 0.5 dB relative attenuation at 20 kHz the time shift between 20 Hz and 20 kHz is only 300 nanosec (which is 20 deg phase shift). This is 1000 times lower than the lowest group delay difference that a human ear can resolve in the most sensitive range (at 2 kHz).
The audibility of group delay ‘distortion’ with the interaural time delay (ITD) are often confused. ITD is important for binaural hearing and localization, the audibility of group delay ‘distortion’ is about how humans can hear transient smearing.
Dispersion at audio frequencies is only a problem with very long cables – cables which are at least several kilometers long. But in this case the amplitude response will be bad too, not just the phase and – what is interesting – correcting the amplitude response simply cures phase and timing problems.
Audio cables that carry low level signals require protection against EMI (Electromagnetic Interference). RFI (Radio Frequency Interference) is only a concern at those frequencies where the cable becomes an antenna. Therefore interconnect cables are shielded and – in the vast majority of cables – the shield acts as a signal return too. Audio cables have spiral wrapped shield and despite being the simplest and cheapest shielding method, it is enough for audio applications. In order to lower RFI, amplifiers have low pass filters at their input (effective above 1 MHz).
There are few problems with interconnect cables, e.g. in cheaper cables sometimes the wires break close to the connector (this may happen due to the regular cleaning of DVD player, stereo receiver). In this case the solution is a cable with a higher quality strain relief. On the other hand wasting a lot of money for exotic, hi-end interconnect cables is unnecessary.
Tomi Engdahl says:
Near field vs Far field speakers
https://www.youtube.com/watch?v=pdAI1p-TQkM
What’s the difference between near-field and far-field loudspeakers?
Tomi Engdahl says:
Love music or HiFi?
https://www.youtube.com/watch?v=L_JRMdaOyF8
Do audiophiles love music or their HiFi systems more? Paul answers this age old question.
Tomi Engdahl says:
Generally it is usually a good idea to avoid ceramic, electrolyte and tantalumcapacitors on audio path. There are though some exceptions to those rules.
Wima MKP 10, Vishay ROE 1837 are both good polypropylene capacitors for audio uses.
Tomi Engdahl says:
Cornell Dubilier has a handy online calculator for calculating factors related to electrolytic lifespan. Basically, if you derate temperature, working voltage, ripple current, etc., a cheap cap from a reputable manufacturer can last a long time. See: https://www.cde.com/Pluglet/Pluglet_CDE_Applet_Intro.html
Tomi Engdahl says:
Some modern ceramic formulations are basically sonically invisible as well in testing. The c0g formulation is a near perfect dielectric.
Tomi Engdahl says:
Difference between X7R, X5R, X8R, Z5U,Y5V, X7S, C0G Capacitor dielectrics
https://www.raviyp.com/difference-between-x7r-x5r-x8r-z5u-y5v-x7s-c0g-capacitor-dielectrics/
Tomi Engdahl says:
MKS2 or MKP from Wima are a good standard. Also Vishay 1837 are very good because they are very close in tolerance.
Use them in filters.
There are tons of exotic parts, big fat tightly wound oily and who knows what.
Tomi Engdahl says:
WIMA / MKP / Film / Polyester / Polypropilene
Works all the same.
Do not use Ceramic unless NP0.
Tomi Engdahl says:
I think that the first question is “what does better mean”. In what context? Angry electrician, deaf PA jockey, average listener without a “critical system”?
How often does the owner listen to live concerts, are they acoustic instruments without PA or electronic?
At what level of perception does the owner listen? Casual in the same room, casual throughout the house, stares at speakers for an hour, hears the grass grow?
Reads audio publications, believes audio publications, is disgusted by audio publications?
Is interested in test confirmation of results, copies and pastes others results?
If we can honestly answer these questions, the answer to “what is better” could actually provide results supporting the beliefs and hearing capacity of the listener.
I personally think that one could be happy with many amplifier architectures if they match the needs.
Tomi Engdahl says:
how about subjective sound quality / dollar invested.
guess it’s subjective…
Tomi Engdahl says:
My firm belief is that most DIY posts about hardware are from people that desparately need training in perception.
There is a huge delta between flat frequency response/low noise and inspired music. For those at a primitive perception level (frequency response snd signal to noise), what is the difference between dc blocking at the output? Acoustically none. For the angry electrician, just knowing that a cap is in the output causes allergic reaction – or another anger could be that this is all inaudible.
We can create scenes for many categoriez
Tomi Engdahl says:
MKT have high distortion compared to MKP. I would suggest to always use at least MKP. There is kind of distortion measurable only with unsymmetrical signal and it shows MKT distortion is high, and MKP are much superior with real music signals.
There is NO definitive answer as to what color or material will sound best. Seems most are putting the cart before the horse without knowing the impedances, application, why you are attempting this etc….etc…..
WIMA / MKP / Film / Polyester / Polypropilene
Works all the same.
Do not use Ceramic unless NP0.
No, they do not. MKT do not sound good and they distort real music signals.
any measurement proof about the use of MKP generating distortion on low level signals?
I’m guessing “he used his ears.”
IT seems MKP are distortionless.
Tomi Engdahl says:
typical unbalanced audio cables have capacitance of around 70 to 250 pF per meter between signal wire and shield.
Tomi Engdahl says:
Capacitor testing
http://www.humblehomemadehifi.com/Cap.html
Tomi Engdahl says:
Using Transformers: To Transform Audio
https://tapeop.com/interviews/76/transformers/
A transformer is a device that transfers electrical energy from one circuit to another via inductively coupled conductors — coils of insulated wire wound (most often) around a ferromagnetic core. Transformers are useful in audio recording, as they can block DC voltage and facilitate electrical isolation between gear, but they also shape the sound of signals sent through them by introducing subtle, often very desirable “coloration.” This may be a result of any combination of frequency response, time response, distortion or a number other factors for a particular transformer. These effects can be especially attractive when working in the digital realm, where sounds can be perceived as too “cold” or “digital.”
We always hear how certain transformers in a piece of recording equipment add to the quality of its sound. If these transformers are so great, why not skip all the electronics and strap bare transformers into the audio path directly?
when he ran a pretty crispy sounding master through a pair of vintage Marinar transformers that he had lifted from a Neve module. The sound was just right for this record — fat lows, punchy mids and a silky top. I personally hadn’t had a chance to do much with this idea until I recently pillaged my repair guy’s stock bins, and now I’m hooked on trying all kinds of transformers in all kinds of situations.
What you’ll need are 600 ohm to 600 ohm “matching” transformers. These will generally work properly with the gear in our racks. Be careful of center-tapped transformers (center tap to ground). If these are exposed to +48 volts (from phantom power) in your system, they could easily be damaged.
I’ve now tried transformers for processing all types of sources, and have fallen in love with many of the sounds I’m getting.
My favorites so far have been a pair of vintage Triad HS-66s, as they add a mid-range thickness to the signal that really warms things up without obscuring the lows or the highs. On a full mix they add a heft and three-dimensional quality to the sound that, while certainly not achieving the full effect, leans in the direction of a vintage console. On individual instruments they have a fattening effect that’s especially cool on kick drum and bass guitar. Pushing the signal can drive the transformer into distortion — sometimes a desirable lo-fi sound — though the need for an attenuator crops up pretty quickly.
the transformer gave me just that little bit of harmonic complexity that I needed. It was like stirring a little more flour into the gravy, thickening to taste.
Tomi Engdahl says:
High resolution or bright sound?
https://www.youtube.com/watch?v=G1FtEDcswgc
The difference between an overly bright “etched” sound and higher resolution audio can sometimes be hard to tell apart. Paul helps a customer whose choice in equipment is working against him.
Comments:
To me, a highly resolving audio system is a function of the lowest noise floor available from the all of the active components in the system and exceptional timbrel accuracy. I always come back to the source material if my two criteria listed above are inherent in my system. When I play a poor recording it becomes a potential source of brightness to me.
Paul, never apologize for being a straight shooter. These guys need help and getting good reliable info from a pro like yourself is very valuable to us all. Keep up the good work
I can think of 4 brands off the top of my head that are famous for fatiguing speakers and many of their offerings are selling for multiple thousands of dollars. I don’t get it when people ignore these reports and don’t audition them properly. Another set of ‘barely used’ speakers on the used market I guess.
Try first to leave the B&W speaker grills on and avoid toe in of the speakers. This may help (damp) a little bit. Next step should be the room. There you will have to to spend a weekend to try some diffusors or absorbing stuff. Don’t start with selling your expensive gear.
You’re not wrong. I own B&W 804 D2 and as much as I love them for the few things they do right, they are 100% on the bright side of sound. They are resolving but bright. My advice to this guy is to turn treble between -3dB to -5dB. Only way to counter that sizzling top. Room corrections and equipment won’t do a lot for the top end. the speakers are the way they are. I have tried many different pre-amps, amps and cables. None do much for the hot tweeter.
B&W’s upper models were true studio monitors at the time. The brochure clearly said that the tweeter volume could be reduced by a dB (or two) to make them sound in balance. With the underlying idea that reducing tweeter volume should be better than scaling it up.
(An 802 has exactly the same sound characteristics as the 801 used in studios, as you know.)
Congratulations to Paul McGowan. He has the guts to tell the truth in the insane online world of misguided attack and counterattack. Obviously I agree with him! It is my opinion that B&W speakers are a bit harsh in the higher frequencies, possibly a function of the tweeters they use. I am proud to subscribe to his PS Audio podcast, although as a crazy audiophile, I do not own any of their products. Instead, I own hardware that many would think is insanely over-priced.
I like my music loud and I want to feel it, same with movies … If it sounds bright, it’s a deal breaker. That’s the reason I steer clear from speakers with metal dome tweeters… Harsh city!
I always use Joni Mitchell’s ‘Blue’ album to test the brightness of a system or component. It is a brightly mastered album (at least in its earlier versions) and can laser the skin off a custard if partnered with bright speakers. And yet when played on a balanced system it is wonderful. Paul is right – B&W speakers tend to be bright as there is a market for such speakers among folk whose hearing in the upper regions is going off.
Tomi Engdahl says:
Time to re-invent the wheel with expensive square corners
Tomi Engdahl says:
“Occasionally when i touch chasis edge(amplifier) it gives me a mild shock, low leakage current i guess.”
Low leakage current is most common. Sometimes it is possible higher leakage on device but you were well grounded.
“Out of curiosity when i change polarity of ac power cord everything becomes normal. What’s the reason?”
Many modern equipment that use swich mode power supplies have filter capacitors between mains side and chassis. Depending on equipment design there can be two capacitors (designed to be grounded equipment) or one capacitor from one of of the ungrounded power connector pins to case. Depending on mains plug polarity you have it from live to chassis (leakage) or neutral to chassis (almost no leakage).
Traditional transformer can have some leakage that can vary depending on which side of primary is on live or neutral.
“is it dangerous for human being?”
When equipment is properly designed, im good condition and built using proper parts, it is not dangerius.
Tomi Engdahl says:
it is a common practice in many audio power supplies to connect audio circuit ground that is typically connected to chassis to power transformer secondary center pin. Doing that connection does not do practically anything on providing a path from audio circuit to become “grounded” because that whole secondary coil is at floating potential (with some small capacitive coupling to mains side)
Tomi Engdahl says:
Probably has a capacitor from line to chassis ground. in guitar amps, they call this the “death cap”. Again, how are you reversing the cord?
Tomi Engdahl says:
There is a difference between being able to feel a tingle vs being electrocuted. The simple test is to measure voltage from the exposed metal of the component to a solid earth ground WITH a 1500 ohm resistor across the meter. As long as the AC voltage is under .75v you are completely safe. This equals a leakage of .5ma, you might feel it but it’s harmless.
Tomi Engdahl says:
“There is no science to back that up. It is purely a gut level feeling that marketeers pounce on!”
I can agree that it is this quite often in many audio topics. Lots of gut feeling and marketing and usually less than should be science.
“I would certainly hope that quality audio gear has a power supply with adequate filtering!”
You could hope for that, but that’s always not the case. Quite often cheapest consumer crap and minimalist “high end” tube systems or DIY classic tube stuff have the worst power supplies when it comes to filtering.
Tomi Engdahl says:
Does mood affect music?
https://www.youtube.com/watch?v=qtyAPtBNJ-Y
Music affects each of us differently. How much does our mood play a role in our perception and acceptance of music?